PASSWORD Routine quit working after Splitting the Database

I am using Microsoft's Password routine for "causual" protection of forms...

After splitting the database to a frontend and backend I get a 3219 "Invalid Operation" error when entering a Password - the form
that is protected loads regardless.

Snip of the code

frmPASSWORD...
-----------------------------------------------------------------------------------------------------------------------
Option Compare Database

Private Sub CheckPassword_Click()
On Error GoTo Err_CheckPassword_Click

If IsNull(Forms!frmPassword!Text0.Value) Then
                 MsgBox "You cannot enter a blank Password. Try again."
                 Me!Text0.SetFocus
            Else
                 MyPassword = Me!Text0.Value
                 DoCmd.Close acForm, "frmPassword"
            End If

Exit_CheckPassword_Click:
    Exit Sub

Err_CheckPassword_Click:
    MsgBox Err.Description
    Resume Exit_CheckPassword_Click
   
End Sub
Private Sub Command3_Click()
On Error GoTo Err_Command3_Click


    DoCmd.Close

Exit_Command3_Click:
    Exit Sub

Err_Command3_Click:
    MsgBox Err.Description
    Resume Exit_Command3_Click
   
End Sub

Private Sub Text0_AfterUpdate()
If IsNull(Forms!frmPassword!Text0.Value) Then
                 MsgBox "You cannot enter a blank Password. Try again."
                 Me!Text0.SetFocus
            Else
                 MyPassword = Me!Text0.Value
                 DoCmd.Close acForm, "frmPassword"
            End If

Exit_CheckPassword_Click:
    Exit Sub

End Sub

---------------------------------------------------------------------------------------

Code for the OnOpen of the protected Form - where the error occurs:

-------------------------------------------------------------------------------------------------------------------
Private Sub Form_Open(Cancel As Integer)
strRecordSource = Me.RecordSource
TTManual.SetFocus

   Dim Hold As Variant
   Dim tmpKey As Long
   Dim I As Integer
   Dim rs As DAO.Recordset
   Dim db As DAO.Database

   On Error GoTo Error_Handler
   ' Prompt the user for the Password.
   DoCmd.OpenForm "frmPassword", acNormal, , , , acDialog
            Hold = MyPassword
' Open the table that contains the password.
   Set db = CurrentDb
   Set rs = db.OpenRecordset("tblPassword", dbOpenTable)
   rs.Index = "PrimaryKey"
   rs.Seek "=", Me.Name
   If rs.NoMatch Then
      MsgBox "Sorry cannot find password information. Try Again"
      Cancel = -1
   Else
      ' Test to see if the key generated matches the key in
      ' the table; if there is not a match, stop the form
      ' from opening.
      If Not (rs![KeyCode] = KeyCode(CStr(Hold))) Then
         MsgBox "Sorry you entered the wrong password." & _
            "Try again.", vbOKOnly, "Incorrect Password"
         Cancel = -1
      End If
   End If
   rs.Close
   db.Close
   Exit Sub

Error_Handler:
   MsgBox Err.Description, vbOKOnly, "Error #" & Err.Number
   Exit Sub
End Sub
---------------------------------------------------------------------------------------------

Any ideas where to begin?